Effect of clonidine (Haemiton) on plasma renin level and angiotensin sensitivity in man.

The effect of clonidine and of clonidine + spironolactone on renin activity and angiotensin sensitivity has been studied in 15 persons. Clonidine-induced angiotensin pressor dose and renin level reduction have been abolished by spironolactone. The phenomenon is explained by the contrary effects of the two drugs on renin activity and angiotensin sensitivity. Other possible mechanisms of antihypertensive clonidine effect are also discussed.